Testing device for wireless power transfer, and associated method

ABSTRACT

A testing device for use in testing of wireless power transfer is disclosed. The testing device has a housing, a wireless power receiver coil provided in the housing, and a cable extending from the housing at a first end and having a cable connector at a second end. The cable accommodates connection wiring of the wireless power receiver coil. The cable connector comprises a data storage configured to contain characteristic information about the wireless power receiver coil.

CROSS-REFERENCE TO RELATED APPLICATION

The present patent application claims Paris convention priority toSwedish patent application 1550754-4, filed on Jun. 8, 2015, thecontents of which are incorporated herein in their entirety byreference.

TECHNICAL FIELD

The present invention generally relates to the field of wireless powertransfer, and more specifically to testing of wireless power transfer.Even more specifically, the present invention relates to a testingdevice for use in testing of wireless power transfer, the testing devicehaving a wireless power receiver coil. The present invention alsorelates to a method of testing wireless power transfer from a wirelesspower transmitter device having a wireless power transmitter coil.

BACKGROUND

Wireless power transfer is expected to become increasingly popular, forinstance for wireless battery charging of mobile devices such as, forinstance, mobile terminals, tablet computers, laptop computers, cameras,audio players, rechargeable toothbrushes, wireless headsets, as well asvarious other consumer products and appliances.

The Wireless Power Consortium has developed a wireless power transferstandard known as Qi. Other known wireless power transfer approachesinclude Alliance for Wireless Power, and Power Matters Alliance.

The wireless power transfer standard known as Qi by the Wireless PowerConsortium will be referred to, without limitation, throughout thisdocument as the presently preferred wireless power transfer mannerapplicable to the present invention. However, the invention maygenerally be applied also to other wireless power transfer standards orapproaches, including but not limited to the ones mentioned above. Also,this disclosure is not limited to any particular power range butincludes, without limitation, low power applications as well as mediumpower applications and high power applications.

Operation of devices that comply with Qi relies on magnetic inductionbetween planar coils. Two kinds of devices are involved, namely devicesthat provide wireless power (referred to as base stations), and devicesthat consume wireless power (referred to as mobile devices). Powertransfer takes place from a base station to a mobile device. For thispurpose, a base station contains a subsystem (a power transmitter) thatcomprises a primary coil, whereas a mobile device contains a subsystem(a power receiver) that comprises a secondary coil. In operation, theprimary coil and the secondary coil will constitute the two halves of acoreless resonant transformer.

Typically, a base station has a flat surface, on top of which a user canplace one or more mobile devices so as to enjoy wireless batterycharging or operational power supply for the mobile device(s) placed onthe base station.

As with most electric power applications, there is a need to test thedevices involved in wireless power transfer. There are several reasonswhy testing is important; regulatory requirements, manufacturerliability and market competition are a few examples.

In wireless power transfer, there is a desire to measure the energyreceived by the mobile device in order to assess the capability of thewireless power transmitter device 20 to deliver wireless power accordingto a given rating, criterion or standard, and/or to verify compliancewith an applicable wireless power transfer standard.

Also, it is desired to test the communication between the transmitter(base station) and receiver (mobile device). In, for instance, Qi MediumPower, the wireless power transfer is controlled by way of complexhandshaking and signaling between the devices, i.e. a bidirectionalcommunication between the devices. In, for instance, Qi Low Power, thereis a unidirectional communication where the receiver (mobile device)sends control messages to the transmitter (base station).

Moreover, there is a desire to evaluate the thermal exposure of a mobiledevice when being subjected to wireless power transfer from a wirelesspower transmitter. This is because during operation, heat will begenerated by magnetic induction in the secondary coil of the powerreceiver, i.e. in the mobile device. Also, the power transmitter in thebase station will generate heat that will be conveyed from the basestation to the mobile device. If the thermal exposure for the mobiledevice becomes excessive, several undesired effects may arise. Forinstance, vital components may be damaged in the mobile device, such asfor instance a lithium ion battery or electronic circuitry in asmartphone. At severe overheating, objects in the vicinity of the mobiledevice may be damaged and even cause a fire or toxic smoke hazard.Furthermore, the duration of the charging period may be prolonged, sinceprotective circuitry in the mobile device may intervene to reduce oreven suspend the charging power until the temperature has been reducedagain.

Base stations can be tested by the provision of respective testingdevices which comprise a wireless power receiver coil that matches thewireless power transmitter coil of the base station to be tested. Byplacing such a testing device on or otherwise adjacent to the basestation and connecting the testing device to a host device, the hostdevice may run various wireless power transfer tests by driving thewireless power receiver coil in a manner which mimics the indentedoperation of a mobile device from the base station's perspective, Bymonitoring the resulting behavior of the testing device, the host devicemay evaluate the performance of the base station and also identifypotentially abnormal behavior of the base station. Since there areseveral different types of wireless power coils on the market, severaldifferent types of testing devices may also be required.

However, to perform these tests accurately, the host device needs toknow certain information about the wireless power receiver coil. Suchinformation can be hard-coded into the test session program run by thehost device, or retrieved from a settings file or database at runtime.Alternatively, it may be entered manually by a test operator before orduring the execution of the test session program.

The present inventor has identified problems and shortcomings with theseapproaches, since they are potentially error-prone and complicated.Relevant information about the wireless power receiver coil may bemissing or incorrect. Manual approaches may be subject to errors in dataentry. Also, there is a risk of mixing up different instances of testingdevices, such that a test operator may intend to connect a certaintesting device (having a certain specific type of wireless powerreceiver coil) in order to run tests on that receiver coil, butinadvertently connects another testing device (having another specifictype of wireless power receiver coil) to the host device. The outcome ofthe test session will therefore be unreliable, misleading or evendangerous.

Hence, there is an expected need among different interest groups to beable to perform improved tests of wireless power transfer, taking theproblems and shortcomings listed above into account. Such interestgroups may for instance involve any of the following: developers,manufacturers or suppliers of wireless power transmitter devices; testor compliance entities in the field of wireless power transfer; and testor compliance entities in the field of consumer product safety.

SUMMARY OF THE DISCLOSURE

It is accordingly an object of the present invention to offerimprovements in the technical field of wireless power transfer.

A first aspect of the present invention is a testing device for use intesting of wireless power transfer. The testing device comprises ahousing, a wireless power receiver coil provided in the housing, and acable extending from the housing at a first end and having a cableconnector at a second end. The cable accommodates connection wiring ofthe wireless power receiver coil. The cable connector comprises a datastorage, such as an electronic memory, configured to containcharacteristic information about the wireless power receiver coil.

Advantageously, the characteristic information about the wireless powerreceiver coil comprises a type or class of the wireless power receivercoil.

Also, the characteristic information about the wireless power receivercoil may advantageously further comprise one or more of the following: aunique identifier of the wireless power receiver coil; an inductancevalue of the wireless power receiver coil; a first resonance frequencyof the wireless power receiver coil, the first resonance frequency beingan operation resonance frequency for wireless power transfer; a secondresonance frequency of the wireless power receiver coil, the secondresonance frequency being a detection resonance frequency for wirelesspower transfer; a first equivalent series resistance, ESR, value for thewireless power receiver coil at a first frequency; a second equivalentseries resistance, ESR, value for the wireless power receiver coil at asecond frequency; a first Q value for the wireless power receiver coilat the first frequency; and a second Q value for the wireless powerreceiver coil at the second frequency.

In a preferred embodiment, the cable connector has a connector housingand a printed circuit board confined within the connector housing,wherein the data storage is mounted on the printed circuit board.

Also, the cable connector may advantageously comprise a plurality ofconnector terminals, wherein the data storage is connected to at leastone of the connector terminals, and wherein the characteristicinformation about the wireless power receiver coil is readable by a hostdevice for testing of wireless power transfer.

The testing device may further comprise a sensor for detecting anoperation condition of the testing device, wherein an output of thesensor is connected to at least one of the connector terminals and isreadable by the host device for testing of wireless power transfer.

Additionally or alternatively, the testing device may further comprise astatus indicator for indicating a status of the testing device, whereinan input of the status indicator is connected to at least one of theconnector terminals and is drivable by the host device for testing ofwireless power transfer.

In one advantageous embodiment, the printed circuit board furthercomprises tuning circuitry for the wireless power receiver coil. Suchtuning circuitry may comprise a first capacitor for tuning of anoperation resonance frequency for wireless power transfer, and a secondcapacitor for tuning of a detection resonance frequency for wirelesspower transfer.

Advantageously, the characteristic information about the wireless powerreceiver coil may further comprise respective capacitance values of suchfirst and second capacitors.

In one embodiment, the housing has a lower housing part with a bottomside adapted for placement on a surface of a wireless power transmitterdevice having a wireless power transmitter coil, and an upper housingpart.

The testing device may advantageously be adapted for use with thewireless power transmitter device in the form of a wireless charger.

A second aspect of the present invention is a method of testing wirelesspower transfer from a wireless power transmitter device having awireless power transmitter coil. The method involves:

providing a testing device having a housing, a wireless power receivercoil provided therein, and a cable extending from the housing at a firstend and having a cable connector at a second end, the cableaccommodating connection wiring of the wireless power receiver coil;

providing a host device, the host device comprising a processing meansand one or a plurality of cable connector inputs;

placing the testing device on, at or near the wireless power transmitterdevice;

connecting the cable connector of the cable of the testing device to oneof said one or a plurality of cable connector inputs;

reading, by the processing means, data from a data storage of thetesting device, wherein the data comprises characteristic informationabout the wireless power receiver coil in the testing device; and

controlling, by the processing means and based on the characteristicinformation about the wireless power receiver coil, a session fortesting wireless power transfer which involves the wireless powertransmitter device and the testing device.

In one or more embodiments, controlling a session for testing wirelesspower transfer comprises:

checking the characteristic information to verify at least one parameterof the wireless power receiver coil; and

initiating the session for testing wireless power transfer only uponsuccessful verification of the parameter of the wireless power receivercoil.

Advantageously, providing a testing device involves providing thetesting device as defined for the first aspect of the invention.

Embodiments of the invention are defined by the appended dependentclaims and are further explained in the detailed description section aswell as on the drawings.

It should be emphasized that the term “comprises/comprising” when usedin this specification is taken to specify the presence of statedfeatures, integers, steps, or components, but does not preclude thepresence or addition of one or more other features, integers, steps,components, or groups thereof All terms used in the claims are to beinterpreted according to their ordinary meaning in the technical field,unless explicitly defined otherwise herein. All references to “a/an/the[element, device, component, means, step, etc]” are to be interpretedopenly as referring to at least one instance of the element, device,component, means, step, etc., unless explicitly stated otherwise. Thesteps of any method disclosed herein do not have to be performed in theexact order disclosed, unless explicitly stated.

Directions and orientations is three-dimensional space for the testingdevice as described herein are generally expressed with respect to ahorizontal orientation for the testing device, corresponding to thetesting device lying on a horizontal surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Objects, features and advantages of embodiments of the invention willappear from the following detailed description, reference being made tothe accompanying drawings.

FIG. 1 is a schematic block diagram of a wireless power transmitterdevice for wireless power transfer to a mobile device.

FIG. 2 is a schematic block diagram of a setup for testing of wirelesspower transfer, including a testing device, a wireless power transmitterdevice and a host device.

FIG. 3 is an isometric view of the testing device according to oneembodiment, seen in an assembled state, the testing device having acable with a cable connector for connection to the host device.

FIG. 4 is an isometric view of the testing device of FIG. 3, now seen ina disassembled state.

FIG. 5 is a schematic circuit diagram of a printed circuit board withinthe cable connector, the printed circuit board comprising a data storageconfigured to contain characteristic information about a wireless powerreceiver coil of the testing device.

FIG. 6 is a schematic side view of the host device in one embodiment,having a single cable connector input for a testing device as referredto above.

FIG. 7 is a schematic side view of the host device in anotherembodiment, having a plurality of cable connector inputs for concurrentconnection of several testing devices as referred to above.

FIG. 8 is a flowchart diagram of a method of testing wireless powertransfer from a wireless power transmitter device having a wirelesspower transmitter coil, involving use of a testing device as referred toabove.

DETAILED DESCRIPTION

Embodiments of the invention will now be described with reference to theaccompanying drawings. The invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Theterminology used in the detailed description of the particularembodiments illustrated in the accompanying drawings is not intended tobe limiting of the invention. In the drawings, like numbers refer tolike elements.

FIG. 1 illustrates a wireless power transmitter device 20 for wirelesspower transfer to a mobile device 10. The mobile device may, forinstance, be a mobile terminal (e.g. smartphone) 10 a, tablet computer10 b (e.g. surfpad), laptop computer 10 c, camera, audio player,rechargeable toothbrush, wireless headset, or another kind of consumerproduct or appliance.

The wireless power transfer will be described as being compliant withthe Qi standard by the Wireless Power Consortium; hence, the wirelesspower transmitter device 20 is a base station in the Qi terminology.However, as already mentioned, the invention is generally applicablealso to other wireless power transfer standards or approaches, includingbut not limited to the ones mentioned in the Background section.

The wireless power transmitter device 20 comprises a wireless powertransmitter 22 having a wireless power transmitter coil 24.Correspondingly, the mobile device 10 comprises a wireless powerreceiver 12 having a wireless power receiver coil 14. In operation, thewireless power transmitter device 20 will transfer power wirelessly tothe mobile device 10 by way of magnetic induction 18 via the wirelesspower transmitter coil 24 and wireless power receiver coil 14.

The power received by the wireless power receiver coil 14 will drive aload 16 in the mobile device 10. Typically, the load 16 may be arechargeable battery, such as a lithium ion battery; hence, the wirelesspower transmitter device 20 will act as a wireless power charger for themobile device 10. In another scenario, the load 16 may be electroniccircuitry in the mobile device, wherein the wireless power transmitterdevice 20 will act as a wireless power supply for the mobile device 10.

As explained in the Background section, it is desired to be able to testthe performance of the wireless power transmitter device 20 with respectto its intended use with mobile devices, such as mobile device 10.

To this end, a testing device 30 has been provided, embodiments of whichare illustrated in FIGS. 2-5. There is also provided an associatedmethod of testing wireless power transfer from a wireless powertransmitter device having a wireless power transmitter coil. This methodis illustrated in FIG. 8.

FIG. 2 is a schematic block diagram which shows a testing device 30 foruse with a wireless power transmitter device 20 under the control of ahost device 40. The wireless power transmitter device 20 has a wirelesspower transmitter 22 and a wireless power transmitter coil 24, and maybe identical to the wireless power transmitter device 20 in FIG. 1. Aswill be described in more detail below, the testing device 30 has awireless power receiver 32 with a wireless power receiver coil 34 whichmatches the wireless power transmitter coil 24 of the wireless powertransmitter 22. A suitable load 36 may be provided to handle excesspower received by the wireless power receiver coil 34 in the testingdevice 30. For instance, a suitably dimensioned resistor may be used.

The testing device 30 is connected to the host device 40 via a link 35.Schematic side views of different embodiments of the host device 40 areseen in FIGS. 6 and 7. In the disclosed embodiments, the link 35includes a cable 60 which will be described in more detail later. Inoperation during a test session, the wireless power transmitter device20 will transfer power wirelessly to the testing device 30 by way ofmagnetic induction 18 via the wireless power transmitter coil 24 and thewireless power receiver coil 34.

The testing device 30 may optionally have one or more sensors 31 fordetecting an operation condition of the testing device 30 during thetest session. Measurement data from the sensor(s) 31 may be provided viaan interface 33 in the testing device 30 to the host device 40 via aninterface 41, as is seen in FIG. 2. For instance, the sensor(s) 31 maybe thermo sensory means capable of measuring the thermal exposure of thetesting device 30 caused by the wireless power transfer from thewireless power transmitter device 20. Suitable thermo sensory means aredisclosed in detail in Swedish patent applications 1451306-3 and1550340-2, the contents of which are incorporated herein by reference intheir entirety.

The testing device 30 may optionally have one or more status indicators32 for indicating a status of the testing device during the testsession. The status indicator(s) 32 may be drivable by the host device40 via the aforementioned interfaces 33, 41. Examples of statusindicators include light emitting diodes, lamps, displays, buzzers,speakers and vibrators.

The host device 40 also has processing means 42 for measuring/analyzingthe received power by the testing device 30 over the link 35, andprocessing any measurement data received from the testing device 30 ifapplicable. The processing means 42 may comprise a programmable device,such as a microcontroller, central processing unit (CPU), digital signalprocessor (DSP) or field-programmable gate array (FPGA) with appropriatesoftware and/or firmware, and/or dedicated hardware such as anapplication-specific integrated circuit (ASIC).

Furthermore, the host device 40 may have reporting means 43 forcommunicating or presenting results obtained by the processing means 42.This may involve presentation of graphical information on a local userinterface (e.g. display) of the host device 40, generating of visualand/or audible alarms, or communication of information to an externaldevice, as seen at 45 in FIG. 2.

Embodiments of the testing device 30 will now be described withreference to FIGS. 3-5. Other embodiments than the illustrated ones areof course possible within the scope of the invention.

As seen particularly in FIG. 3, the testing device 30 in the disclosedembodiment essentially has the shape of a thin box with rounded edgesand corners. The testing device 30 has a housing 50 having a lowerhousing part 51 and an upper housing part 52. The lower housing part 51has a bottom side adapted for placement on a surface of the wirelesspower transmitter device 20. The upper housing part 52 has a top sideopposite to the bottom side. The lower housing part 51 may be made ofplastic or another material suitable for admitting the inductivecoupling 18 between the wireless power transmitter coil 24 of thewireless power transmitter device 20 and the wireless power receivercoil 34 of the wireless power receiver 32. The upper housing part 52 mayalso be made of plastic, or alternatively of a material, such asaluminium or glass, having heat dissipation properties similar to atypical mobile device that the wireless power transmitter device 20 isdesigned for use with.

In the disclosed embodiment of FIG. 3, the testing device 30 has a cable60 which constitutes or at least forms a part of the link 35 to the hostdevice 40, as referred to above for FIG. 2. The cable 60 has a cableconnector 70 which is connectable to the host device 40.

Reference is now made to the exploded isometric views in FIG. 4,illustrating the disclosed embodiment of the testing device 30 in adisassembled state. The wireless power receiver coil 34 is providedinside the housing 50. As explained above, the testing device 30 mayoptionally include one or more sensors 31, one or more status indicators30, and the interface 35. None of these optional elements are shown inFIG. 4 for reasons of brevity.

As seen in FIG. 4, the cable 60 extends from the housing 50 at a firstend 61. The cable connector 70 is at an opposite second end 62 of thecable 60. The cable 60 accommodates connection wiring 63 of the wirelesspower receiver coil 34. In the disclosed embodiment, the connectionwiring 63 is the same physical wiring as makes up the loops of thewireless power receiver coil 34; the ends of the coil 34 thus continueuninterrupted through the cable 60 to the cable connector 70. Thisarrangement is believed to be advantageous, since a signal junctionbetween the loops of the coil 34 and the start of the cable 60 (at thefirst end 61) has been avoided. In other embodiments, however, it may bepossible to have a separate connection wiring 63 which connects to theloops of the coil 34 somewhere at the first end 61.

The cable connector 70 has a connector housing comprising a rear part 71and a front part 72. The front part 72 can be threaded onto the rearpart 71 thanks to a threading 71 a on the rear part 71 and a matchingthreading inside the front part 72.

The front part 72 has a protruding plug 74 which serves for mating witha corresponding recess in a socket on the host device 40. The protrudingplug 74 has a plurality of cable connector terminals 77 at the frontside of the plug 74.

Inside the cable connector 70 there is an insert member 73 having aresilient element 75 which is actuatable by pushing on a button 76 onthe outside of the front part 72. The elements 75 and 76 serve toprovide a secure engagement when the cable connector 70 is inserted in acorresponding input or socket on the host device 40 (see sockets 41 and41 ₁-41 _(n) in FIG. 6 and FIG. 7, respectively).

In the disclosed embodiment, the cable connector 70 is a five-terminalfemale XLR connector. However, other types of connectors are equallypossible, both in terms of the type of cable connector, and the numberand “gender” (male/female) of the cable connector terminals 77.

As seen in FIG. 4, a printed circuit board 80 is confined within theconnector housing 71, 72. A schematic circuit diagram of the printedcircuit board 80 within the cable connector 70, with a data storage 82mounted thereon, is shown in FIG. 5.

The data storage 82 is configured to contain characteristic information83 about the wireless power receiver coil 34. In the disclosedembodiment, the data storage 82 is an electronic memory, or morespecifically an EEPROM memory, such as for instance the integratedcircuit DS24B33+ by Maxim Integrated, 160 Rio Robles, San Jose, Calif.95134, USA. Various other types of electronic memories or other datastorages may also be used, as is readily realized by a skilled person.

The data storage 82 is connected to at least one of the connectorterminals 77 of the cable connector 70, as is seen at 84 in FIG. 5. Inthe disclosed embodiment of FIG. 5, the data storage 82 is connected tothe connector terminals 77 ₂, 77 ₄, where terminal 77 ₂ may be aterminal for data reading & voltage supply to the data storage 82, andterminal 77 ₄ may be a terminal for ground. The characteristicinformation 83 about the wireless power receiver coil 34, as stored inthe data storage 82, is therefore readable by the host device 40 fortesting of wireless power transfer.

In embodiments where the testing device 30 includes as sensor 31 fordetecting an operation condition of the testing device, an output of thesensor 31 may be connected to at least one of the connector terminals77, such as for instance connector terminals 77 ₃, 77 ₄, to render itreadable by the host device 40 for testing of wireless power transfer.

Likewise, in embodiments where the testing device 30 includes a statusindicator 32 for indicating a status of the testing device 30, an inputof the status indicator 32 may be connected to at least one of theconnector terminals 77, such as for instance connector terminals 77 ₃,77 ₄, to render it controllable by the host device 40 for testing ofwireless power transfer.

If need be, the number of connector terminals 77 may be increased inorder to make them available for such sensor(s) 31 and/or statusindicator(s) 32. Alternatively, the communication between the hostdevice 40 and any or all of these optional elements may occur over aseparate link (wired or wireless).

The characteristic information 83 about the wireless power receiver coil34 advantageously comprises a type or class of the wireless powerreceiver coil 34. For instance, when the wireless power receiver coil 34is a Qi low power coil, its type or class may be indicated in thecharacteristic information 83 as a value A, B, C, D,

As will appear in more detail later with reference to the forthcomingdescription of the testing method illustrated in FIG. 8, the indicationof the actual coil type of the wireless power receiver coil 34 in thecharacteristic information 83 will allow for the host device 40 todetect an error situation when a test operator inadvertently is about tostart a test session for another instance of the test device 30 (i.e.,based upon another coil type), than what was intended.

Advantageously, the characteristic information 83 about the wirelesspower receiver coil 34 also comprises the following additional data, orparts thereof:

-   -   A unique identifier of the wireless power receiver coil 34. The        unique identifier may, for instance, be given as a serial        number.    -   An inductance value of the wireless power receiver coil 34,        expressed as a numerical value in H (or magnitudes thereof).    -   A first resonance frequency of the wireless power receiver coil        34, expressed as a numerical value in Hz (or magnitudes        thereof). The first resonance frequency will typically be an        operation resonance frequency for wireless power transfer. For        instance, for Qi low power applications, the first resonance        frequency may be at about 100 kHz.    -   A second resonance frequency of the wireless power receiver coil        34, expressed as a numerical value in Hz (or magnitudes        thereof). The second resonance frequency will typically be a        detection resonance frequency for wireless power transfer. For        Qi low power applications, the second resonance frequency may be        at about 1 MHz.    -   A first equivalent series resistance, ESR, value for the        wireless power receiver coil 34 at a first frequency, which may        be aforesaid first resonance frequency. The first ESR value may        be expressed as a numerical value in Ω (or magnitudes thereof).    -   A second equivalent series resistance, ESR, value for the        wireless power receiver coil 34 at a second frequency, which may        be different from aforesaid first resonance frequency. The        second ESR value may be expressed as a numerical value in Ω (or        magnitudes thereof).    -   A first Q value for the wireless power receiver coil 34 at the        first frequency.    -   A second Q value for the wireless power receiver coil 34 at the        second frequency.

As will appear in more detail later with reference to the forthcomingdescription of the testing method illustrated in FIG. 8, including anyor all of the additional data in the characteristic information 83 willallow for the host device 40 to perform an accurate test session, beingbased on exact respective parameter values of the individual wirelesspower receiver coil 34. Also, it will allow for the host device 40 toperform compliance tests with respect to an applicable wireless powertransfer standard, such as Qi.

In an advantageous embodiment, as is shown in FIG. 5, the printedcircuit board 80 inside the cable connector 70 further comprises tuningcircuitry 86 for the wireless power receiver coil 34. Hence, the tuningcircuitry 86 may comprise a first capacitor C1 for tuning of anoperation resonance frequency for wireless power transfer, and a secondcapacitor C2 for tuning of a detection resonance frequency for wirelesspower transfer. In this advantageous embodiment, the characteristicinformation 83 about the wireless power receiver coil 34 may furthercomprise the respective capacitance values of the first capacitor C1 andsecond capacitor C2, expressed in F (or magnitudes thereof).

This represents a very efficient and yet accurate implementation, whereno separate tuning circuitry for the coil 34 will have to be provided inthe housing 50 thereof. Instead, the tuning circuitry 86 as well as thedata storage 82 will be safely accommodated inside the cable connector70.

FIG. 8 is a flowchart diagram of a method of testing wireless powertransfer from a wireless power transmitter device (such as device 20 asreferred to above), having a wireless power transmitter coil (such ascoil 24 as referred to above). The method involves the following.

In a first step 110, a testing device is provided which has a wirelesspower receiver coil hopefully matching the wireless power transmittercoil 24, The provided testing device also has a housing, a cable whichextends from the housing at a first end and a cable connector at asecond end of the cable, wherein the cable accommodates connectionwiring of the wireless power receiver coil. The testing device providedin step 110 may advantageously be the testing device 30 as describedabove for FIGS. 2-5.

In a second step 120, a host device (such as host device 40 as referredto above) is provided which comprises a processing means (such asprocessing means 42 as referred to above) and one or a plurality ofcable connector inputs (such as sockets 41 or 41 ₁-41 _(n) as referredto above).

In a third step 130, the testing device 30 is placed on, at or near thewireless power transmitter device 20.

In a fourth step 140, the cable connector 70 of the cable 60 of thetesting device 30 is connected to the single cable connector input 41(situation in FIG. 6) or one of the available cable connector inputs 41₁-41 _(n) (situation in FIG. 7) of the host device 40, as the case maybe.

In a fifth step 150, the processing means 42 reads data from a datastorage (such as data storage 82 as referred to above) of the testingdevice 30. The data comprises characteristic information 83 about thewireless power receiver coil 34 in the testing device 30.

In a sixth step 160, the processing means 42 controls—based on thecharacteristic information 83 about the wireless power receiver coil34—a session for testing wireless power transfer which involves thewireless power transmitter device 20 and the testing device 30.

This may, for instance, involve checking the characteristic information83 to verify at least one parameter of the wireless power receiver coil34. The parameter to be verified may advantageously be the type or classof the coil 34. By checking the expected type or class of the coil 34(based on hard-coded data in the test session program run by theprocessing means 42, reference data read from a settings file ordatabase, or data having been manually input by the test operator duringexecution of the test session program) against the type or class of thecoil 34 as indicated by the characteristic information 83 read from thedata storage 82 of the testing device 30, the processing means 42 maydetect if the two does not match. Such a mix-up may occur because oferrors in the hard-coded data, in the reference data read from asettings file or database, or in the manual entry made by the testoperator.

Alternatively, such a mix-up may occur because the test operatorinadvertently connects a different instance of the testing device 30 tothe host device 40 than the intended one, or inadvertently connectsdifferent instances of the testing device 30 to the incorrect cableconnector inputs 41 ₁-41 _(n) when the host device 40 has several suchinputs like in the embodiment of FIG. 7.

The processing 42 will accordingly refrain from initiating or continuingthe test session if the verification fails, and hence only initiate orcontinue the test session upon successful verification of the type orclass of the wireless power receiver coil 34.

In another implementation example of step 160 in FIG. 8, the processingmeans 42 of the host device 40 retrieves any or all of the additionalparameter values of the wireless power receiver coil 34 as stored in thedata storage 82, and uses it or them for performing accuratemeasurements of, for instance, the capability of the wireless powertransmitter device 20 to deliver wireless power according to a givenrating, criterion or standard.

In yet another implementation example of step 160 in FIG. 8, theprocessing means 42 of the host device 40 uses any or all of theadditional parameter values to perform compliances tests with respect toan applicable wireless power transfer standard, such as Qi.

The equipment and procedures described above will allow testing ofwireless power transfer for the benefit of various potential interestgroups, such as any or all of the following:

-   -   Developers, manufacturers or suppliers of wireless power        transmitter devices,    -   Test or compliance entities in the field of wireless power        transfer,    -   Test or compliance entities in the field of consumer product        safety.

The invention has been described above in detail with reference toembodiments thereof. However, as is readily understood by those skilledin the art, other embodiments are equally possible within the scope ofthe present invention, as defined by the appended claims.

What is claimed is:
 1. A testing device for use in testing of wirelesspower transfer, the testing device comprising: a housing; a wirelesspower receiver coil provided in the housing; and a cable extending fromthe housing at a first end and having a cable connector at a second end,the cable accommodating connection wiring of the wireless power receivercoil, wherein the cable connector comprises a data storage configured tocontain characteristic information about the wireless power receivercoil.
 2. The testing device as defined in claim 1, wherein the datastorage is an electronic memory.
 3. The testing device as defined inclaim 1, wherein the characteristic information about the wireless powerreceiver coil comprises a type or class of the wireless power receivercoil.
 4. The testing device as defined in claim 1, wherein thecharacteristic information about the wireless power receiver coilcomprises one or more of the following: a unique identifier of thewireless power receiver coil, an inductance value of the wireless powerreceiver coil, a first resonance frequency of the wireless powerreceiver coil, the first resonance frequency being an operationresonance frequency for wireless power transfer, a second resonancefrequency of the wireless power receiver coil, the second resonancefrequency being a detection resonance frequency for wireless powertransfer, a first equivalent series resistance, ESR, value for thewireless power receiver coil at a first frequency, a second equivalentseries resistance, ESR, value for the wireless power receiver coil at asecond frequency, a first Q value for the wireless power receiver coilat the first frequency, and a second Q value for the wireless powerreceiver coil at the second frequency.
 5. The testing device as definedin claim 1, the cable connector having a connector housing and a printedcircuit board confined within the connector housing, wherein the datastorage is mounted on the printed circuit board.
 6. The testing deviceas defined in claim 1, the cable connector comprising a plurality ofconnector terminals, wherein the data storage is connected to at leastone of the connector terminals, and wherein the characteristicinformation about the wireless power receiver coil is readable by a hostdevice for testing of wireless power transfer.
 7. The testing device asdefined in claim 6, further comprising a sensor for detecting anoperation condition of the testing device, wherein an output of thesensor is connected to at least one of the connector terminals and isreadable by the host device for testing of wireless power transfer. 8.The testing device as defined in claim 6, further comprising a statusindicator for indicating a status of the testing device, wherein aninput of the status indicator is connected to at least one of theconnector terminals and is drivable by the host device for testing ofwireless power transfer.
 9. The testing device as defined in claim 5,wherein the printed circuit board further comprises tuning circuitry forthe wireless power receiver coil.
 10. The testing device as defined inclaim 9, wherein the tuning circuitry comprises: a first capacitor fortuning of an operation resonance frequency for wireless power transfer;and a second capacitor for tuning of a detection resonance frequency forwireless power transfer.
 11. The testing device as defined in claim 10,wherein the characteristic information about the wireless power receivercoil further comprises respective capacitance values of the firstcapacitor and second capacitor.
 12. The testing device as defined inclaim 1, wherein the housing has a lower housing part with a bottom sideadapted for placement on a surface of a wireless power transmitterdevice having a wireless power transmitter coil, and an upper housingpart.
 13. The testing device as defined in claim 12, wherein the testingdevice is adapted for use with the wireless power transmitter device inthe form of a wireless charger.
 14. A method of testing wireless powertransfer from a wireless power transmitter device having a wirelesspower transmitter coil, the method involving: providing a testing devicehaving a housing, a wireless power receiver coil provided therein, and acable extending from the housing at a first end and having a cableconnector at a second end, the cable accommodating connection wiring ofthe wireless power receiver coil; providing a host device, the hostdevice comprising a processing means and one or a plurality of cableconnector inputs; placing the testing device on, at or near the wirelesspower transmitter device; connecting the cable connector of the cable ofthe testing device to one of said one or a plurality of cable connectorinputs; reading, by the processing means, data from a data storage ofthe testing device, wherein the data comprises characteristicinformation about the wireless power receiver coil in the testingdevice; and controlling, by the processing means and based on thecharacteristic information about the wireless power receiver coil, asession for testing wireless power transfer which involves the wirelesspower transmitter device and the testing device.
 15. The method asdefined in claim 14, wherein controlling a session for testing wirelesspower transfer comprises: checking the characteristic information toverify at least one parameter of the wireless power receiver coil; andinitiating the session for testing wireless power transfer only uponsuccessful verification of the parameter of the wireless power receivercoil.
 16. The method as defined in claim 14, wherein providing a testingdevice involves providing the testing device as defined in claim 1.